India, Nepal, Pakistan

The Western Himalayan Sub-Alpine Conifer Forests [IM0502] represent the frontline of the forested ecoregions in the western Himalayan region, standing against the treeless alpine meadows to the north. This ecoregion plays a critical ecological role as part of the Himalayan ecosystem, with interconnected processes that extend from the Terai and Duar grasslands along the foothills to the high alpine meadows and boulder-strewn scree that lie above the treeline. Several Himalayan birds and mammals exhibit seasonal migrations up and down the steep mountain slopes and depend on contiguous habitat for these movements. If any of the habitat layers are lost or degraded, these movements can be disrupted. Therefore, conservation of this ecoregion is critical to maintain the biodiversity-species and processes-of this youngest and tallest mountain range on Earth.

Scientific Code

(IM0502)

Ecoregion Category

Indo-Malayan

Size

15,300 square miles

Status

Vulnerable

Habitats

Description Location and General DescriptionThe ecoregion represents the sub-alpine conifer forests between 3,000 and 3,500 m in the Himalayan Mountain Range to the west of the Kali Gandaki River in central Nepal. It extends from western Nepal through the northern Indian states of Uttar Pradesh and Himachal Pradesh into Jammu and Kashmir and into eastern Pakistan. The western extents of the Himalayas have more extensive conifer forests of blue pine (Pinus wallichiana), chilgoza pine (Pinus gerardiana), fir (Abies spectabilis), silver fir (Abies pindrow), and spruce (Picea smithiana) than the moister eastern part of the mountain range.

The Middle Himalayas within which the ecoregion lies rise to about 5,000 m. The Middle Himalayas are flanked by the outer Himalayas, also known as the Siwaliks to the south and the Inner Himalayas to the north. The former are composed of alluvial deposits that have washed down from the north for thousands of years and rise to about 1,000 m. The latter contain the tallest peaks on Earth, such as Everest, Makalu, and Dhaulagiri.

The Himalayas are a young mountain range that dates back to a period more than 50 million years ago, when the north-drifting Deccan Plateau collided with the northern Eurasian continent. This collision and subsequent uplift gave rise to the Himalayan Range that now stretches for more than 3,000 km, from Pakistan to Myanmar and beyond.

The Himalayas receive rainfall from the southwestern monsoon that sweeps in from the Bay of Bengal. Most of the monsoon rains are intercepted and expended in the eastern Himalayas; therefore, the western extent receives less precipitation and is drier. This moisture gradient influences the vegetation. For instance, the treeline descends from 4,000 m in the east to about 3,300 m in the west (Kendrick 1989).

The ecoregion has several recognizable forest types based on floral associations. These include pure fir forest (Abies spectabilis), mixed oak-fir forest (Quercus semecarpifolia and Abies spectabilis), mixed rhododendron, fir, and birch forest (Rhododendron campanulatum, Abies spectabilis, and Betula utilis), and mixed coniferous forest (Abies spectabilis, Pinus wallichiana, and Picea smithiana) (Shrestha and Joshi 1997). Cypress (Cupressus torulosa) and deodar (Cedrus deodara) are common above 2,400 m (FAO 1981). Fir (Abies spectabilis) usually forms a continuous belt between 3,000 and 3,500 m on the southern side of the main ranges in central Nepal and can be mixed with Quercus semecarpifolia, Betula utilis, and a rhododendron understory. These sub-alpine areas have a number of economically important species such as Daphne bholua, Arundinaria spp., Betula utilis, and a large number of medicinal plants (Shrestha and Joshi 1997).

Biodiversity FeaturesThis belt of conifer forest sitting immediately below the alpine meadows in the western Himalayas does not have a spectacularly rich fauna or flora but does harbor several focal species of large mammals of conservation importance, including the brown bear (Ursus arctos).

The ecoregion's mammal fauna of fifty-eight species includes one strict endemic rodent (table 1) that has been recorded only from this ecoregion (Corbet and Hill 1992).

Table 1. Endemic and Near-Endemic Mammal Species.

Family Species Muridae Hyperacrius wynnei

An asterisk signifies that the species' range is limited to this ecoregion.

An asterisk signifies that the species' range is limited to this ecoregion.

Other species such as pheasants, and tragopans-e.g., Koklass pheasant (Pucrasia macrolopha), western tragopan (Tragopan melanocephalus), and Himalayan monal (Lophophorus impejanus)-are characteristic of these sub-alpine western Himalayan forests and have low disturbance thresholds. Therefore, they should receive conservation attention and can be used as focal species to monitor habitat integrity and as focal species for conservation management. The Himalayan griffon (Gyps himalayensis), a large bird of prey that soars high above the mountains in these alpine regions and embodies the sense of space in the high Himalayas, can be another focal species. The ecoregion overlaps with an EBA, Western Himalaya (128), identified by BirdLife International (Stattersfield et al. 1998).

Current StatusAlthough the ecoregion is less populated than some of the other Himalayan ecoregions (especially those in the lower elevations), more than 70 percent of the natural habitat has been cleared or degraded. Nevertheless, this ecoregion contains some of the least disturbed forests in the western Himalayas. The eleven protected areas cover 2,400 km2, or about 6 percent of the ecoregion (table 3). Most of the protected areas that fall within the ecoregion are small (<500 km2). However, some of the protected areas are large and overlap across several ecoregions (table 3). Notable among these are Kistwar, Royal Dhorpatan, and Rupti Bhabha.

Ecoregion numbers of protected areas that overlap with additional ecoregions are listed in brackets.

Types and Severity of ThreatsThe steep slopes of some of the high mountains have been deforested for intensive cultivation, although the practice of terracing has greatly reduced erosion. Large-scale collection of the morel mushroom (Morchella esculenta) from this ecoregion by the local people for export coincides with the breeding season of several pheasants and high-altitude mammals. Collection of wood by the local people for their own use and for sale to tourist trekkers and mountaineering parties is also a substantial threat, especially because the high-altitude forests are very slow to regenerate.

Justification of Ecoregion DelineationWe used the Kali Gandaki River as the eastern boundary of the ecoregion. This deep gorge is widely considered to be a biogeographic barrier that defines the eastern and western Himalayan biotas. We used digital forest cover maps from MacKinnon (1997) to identify the distribution of the Himalayan temperate conifer forests to the west of the Kali Gandaki River, bordered by alpine meadows and broadleaf forests to the north and south, respectively. This belt of sub-alpine conifer forest was then placed in the Western Himalayan Sub-Alpine Conifer Forests [IM0502]. All the Himalayan ecoregions are part of Udvardy's Himalayan highlands biogeographic province.

ReferencesReferences for this ecoregion are currently consolidated in one document for the entire Indo-Pacific realm.Indo-Pacific Reference List